He came to the monastery and became a novice when he was about 16 years old, and when he died in 649 he was the monastery's abbot. He wrote a number of instructive books, the most famous of which is The Ladder of Divine Ascent. (It is because of this book that John is known as "Climacus," which means "of the ladder".) It describes how to raise one's soul to God, as if on a ladder. This book is one of the most widely read among Eastern Orthodox Christians, especially during the season of Great Lent which immediately precedes Pascha (Easter), and on the fourth Sunday of Great Lent he is especially commemorated.

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"Nothing equals or excels God's mercies. Therefore, he who despairs is committing suicide. A sign of true repentance is the acknowledgment that we deserve all the afflictions, visible and invisible, that come upon us, and ever greater ones. Moses, after seeing God in the bush, returned again to Egypt, that is, to darkness and to the brick-making of Pharaoh, who was symbolical of the spiritual Pharaoh. But he went back again to the bush, and not only to the bush, but also up the mountain. Whoever has known divine vision will never despair of himself. Job became a beggar, but he became twice as rich again."